Avril's 'stalker' arrested

James Speedy, 30, was booked into jail for investigation of stalking after police searched his Seattle suburban home on Wednesday - the same day the 19-year-old Canadian singer and Grammy nominee played a free concert at a mall south of Seattle.

He later posted $US5,000 ($A6,500) bail and was released.

Officers have been investigating the case since last summer, when they were contacted by Ontario police about harassing letters and emails sent to Lavigne, Detective Jerry Reiner said.

"These did place the family of Avril Lavigne, and Avril Lavigne herself, in fear," Reiner said.

He refused to discuss the content of the messages.

Speedy does not have a listed telephone number. It was unclear whether he had obtained a lawyer.